Lorena Salgado and Stuart Marsland of San Diego wait at the Southwest Airlines counter at San Diego International Airport for a flight to Las Vegas on Thursday, Sept. 8, 2011. The airport closed for the night due to a massive ...
— K.C. Alfred

Good summaritan Dave Eminhizer decided to direct traffic at the intersection of Rancho Bernardo Road and Bernardo Center Drive during a power outage on Thursday in San Diego, California.
— Eduardo Contreras

Good Samaritan Dave Eminhizer decided to direct traffic at the intersection of Rancho Bernardo Road and Bernardo Center Drive during a power outage on Thursday in San Diego, California.
— Eduardo Contreras

San Diego Trolley passengers stranded on a trolley that stopped just after passing the Linda Vista Station when the power went out at 3:40 p.m., walk along the trolley tracks as they near the Old Town Transit Center.
— Howard Lipin

Passengers Tenisha Ross, 17, and Daniel Contreras, 17, wait while stranded on an electric trolley that became disabled in La Mesa. About 90 passengers were stranded and eventually evacuated from the trolley, instructed to take nearby city buses instead. San ...
— James Gregg

Matthew Madrid (left) and Moses Madrid enjoy their dinner at Pho Ca Dao and Grill, a Vietnamese restaurant, in Rancho Bernardo during a power outage on Thursday in San Diego, California.
— Eduardo Contreras

Customers walk to the Sheraton Harbor Island after a massive power outage shut down the county on Thursday, Sept. 8, 2011. The Sheraton was booked to capacity and had some backup power that allowed their restuarants and bars to stay ...
— K.C. Alfred

Cristo Djermanaski wipes his eyes while stranded for more than an hour and a half when the city trolley he was rideing on became disabled in La Mesa. About 90 passengers were stranded and directed to take nearby city buses ...
— James Gregg

San Diego MTS Trolley passengers make their way to city buses after being evacuated from a disabled trolley in La Mesa. About 90 passengers on the trolley were evacuated after waiting over an jour and a half on the tracks. ...
— James Gregg

Customers gather outside of Joe's Bargain Store in City Heights in hopes that the store will open so that they can buy candles, food and water. The store closed it's doors shortly before sundown. San Diego County experienced a massive ...
— James Gregg

Employees, clients and family members hang out outside of Headhunters Salon in La Mesa, power went out in Headhunters Salon in La Mesa. With no electricity, they would lose over $500 in business that afternoon, owner Erica Hunter said. San ...
— James Gregg

Cierra Lewis lifts her child Jasaih Lewis up in the air as they stay outdoors to escape the heat of ther La Mesa apartment. With no electricity for fans or air conditioning, residents preferred the fresh air in an effort ...
— James Gregg

Jerry McCullough, 65, sits outside of his La Mesa apartment to escape the heat of his upstairs unit. With no electricity for fans or air conditioning, many residents of his apartment complex preferred the outdoors to stay cool. San Diego ...
— James Gregg

A customer has a drink at a bar at the Sheraton Harbor Island after a massive power outage shut down the county on Thursday, Sept. 8, 2011. The Sheraton was booked to capacity and had some backup power that allowed ...
— K.C. Alfred

Stranded passengers Kristy Karpaty, and Gerardo Lopez use plug to charge their phones at the Sheraton Harbor Island after a massive power outage shut down the county on Thursday, Sept. 8, 2011. The two were traveling on Southwest Airlines flights ...
— K.C. Alfred

Related

A federal inquiry on Tuesday concluded that electrical-grid operators could have prevented or minimized the Sept. 8 blackout if they had prepared better, maintained real-time communication with one another and monitored key low-voltage transmission lines.

The result of those failures was an outage that affected more than 7 million people in Southern California, Arizona and Baja California.

Authorities long ago traced the start of the outage to maintenance work at a utility switch yard outside Yuma, Ariz. Federal officials set out to explain the deeper mystery of how the failure of one transmission-line segment in the Arizona desert could spread so far against all contingencies.

The blackout hit San Diego County within 11 minutes of the Yuma disruption. It was the immediate aftermath of an automated trip-switch at the San Onofre nuclear plant that blocked power from flowing to the rest of the region — a decision now questioned by federal investigators.

The eight-month probe exposed a lack of awareness about evolving conditions among some of the five operators responsible for balancing the electrical grid.

At least two of those operators — Arizona Public Service Corp. and the Imperial Irrigation District — effectively didn’t perform an analysis of grid conditions for Sept. 8, amid a heat wave with near-peak power demand.

Operators also didn’t actively monitor various low-voltage lines, including those with potential to affect major transmission corridors, and that allowed the original power disruption to spread much farther without prompt intervention.

And the idling of a major power-generation plant in Mexico undergoing maintenance appears to have gone unnoticed by some. The limited power supply was a barrier to stabilizing the grid once failures began.

“Without a really good, real-time picture of your system and your neighbors’, it’s difficult to manage this kind of an event,” said Dave Nevius, senior vice president for the North American Electric Reliability Corp. His group and the Federal Energy Regulatory Commission — often called FERC and NERC — conducted the probe.

FERC and NERC officials stressed that their report was an inquiry, which doesn’t involve enforcement measures such as penalties. They wouldn’t disclose any ongoing investigations into potential violations or other wrongdoing related to the blackout.

Kevin Kelly, general manager of the Imperial Irrigation District, defended the utility and grid operator’s planning. But he also said his group is committed to making improvements based on the report’s recommendations.

A spokeswoman for San Diego Gas & Electric said it wasn’t immediately clear how the utility would proceed in response to the Tuesday report’s findings.

Residents and businesses have filed 7,229 claims against SDG&E, requesting total compensation of about $7 million. The utility has not acted on those claims while liabilities for the outage are clarified among all the electrical operators involved.

In addition, a class-action lawsuit against several utilities has been filed on behalf of business owners seeking damages.

The inquiry by FERC and NERC is aimed at providing guidance to the utility industry on what went wrong and how to avoid similar problems in the future. It is widely considered the most comprehensive look into the power outage.